HTML Entity for Assertion (⊦)
What You'll Learn
How to display the Assertion symbol (⊦), also called the turnstile, in HTML using numeric character references and CSS. In logic and proof theory it commonly reads as “proves” or “entails”; in type theory it appears in judgments such as Γ ⊦ e : τ.
The character is in the Mathematical Operators Unicode block. There is no standard named HTML entity; use ⊦, ⊦, or the CSS escape \22A6 in the content property.
⚡ Quick Reference — Assertion Entity
U+22A6Mathematical Operators block
⊦Hexadecimal reference
⊦Decimal reference
—None (use numeric refs)
Name Value
──────────── ──────────
Unicode U+22A6
Hex code ⊦
HTML code ⊦
Named entity (none)
CSS code \22A6Complete HTML Example
This example shows the Assertion turnstile (⊦) using hexadecimal and decimal character references, plus a CSS content escape on a pseudo-element:
<!DOCTYPE html>
<html>
<head>
<style>
#point:after{
content: "\22A6";
}
</style>
</head>
<body>
<p>Assertion using Hexa Decimal: ⊦</p>
<p>Assertion using HTML Code: ⊦</p>
<p id="point">Assertion using CSS Entity: </p>
</body>
</html>🌐 Browser Support
The Assertion character references are supported in all modern browsers:
👀 Live Preview
See the turnstile in typical notation:
🧠 How It Works
Hexadecimal Code
⊦ uses the Unicode hexadecimal value 22A6 to display the Assertion symbol. The x prefix indicates hexadecimal format.
Decimal HTML Code
⊦ uses the decimal Unicode value 8870 for the same character.
CSS Entity
\22A6 is used in CSS, especially in the content property of ::before and ::after.
No named entity
U+22A6 has no standard named HTML entity in the HTML Living Standard list. Use numeric references or CSS escapes.
Same visual result
Hex, decimal, and CSS methods all produce ⊦. Unicode U+22A6 sits in the Mathematical Operators block (U+2200–U+22FF).
Use Cases
The Assertion turnstile (⊦) commonly appears in these scenarios:
Proof theory, sequent calculus, and “proves” or “entails” in formal logic (e.g. Γ ⊦ φ).
Typing judgments, formal semantics, and language specification (e.g. context ⊦ expression : type).
Logic and discrete-math courses, textbooks, and interactive proof tutors.
Theorem provers (Lean, Coq, Isabelle) and formal-methods write-ups rendered on the web.
CS, logic, and philosophy PDFs mirrored as HTML where Unicode math is inlined.
Add visible text or aria-label (“proves”, “turnstile”) so assistive tech conveys meaning.
The same ⊦ convention appears across languages in logic-heavy content.
💡 Best Practices
Do
- Pick hex or decimal and use it consistently in one document
- Use math-capable fonts (e.g. STIX, Cambria Math) for stable ⊦ alignment
- Explain “proves” or “entails” on first use for general readers
- Reserve
\22A6for CSScontent, not HTML text - Distinguish ⊦ (U+22A6) from ⊨ (U+22A8, true) in notation
Don’t
- Assume a named entity exists for the turnstile
- Confuse assertion ⊦ with double turnstile ⊨ (semantic consequence)
- Drop the symbol into UI with no textual context for screen readers
- Paste CSS escapes directly into HTML body content
- Mix multiple numeric styles without a project convention
Key Takeaways
Two HTML numeric forms render ⊦
⊦ ⊦In CSS, use \22A6 inside content on pseudo-elements
\22A6Unicode U+22A6 is in the Mathematical Operators block
There is no standard named HTML entity for this glyph
Do not confuse ⊦ with ⊨ (“true” / double turnstile for validity)
❓ Frequently Asked Questions
⊦ (hex), ⊦ (decimal), or \22A6 in CSS content. There is no standard named entity.U+22A6 (hex 22A6, decimal 8870). Often called the turnstile; used for syntactic derivability in logic.⊦ or ⊦) belong in markup. The CSS escape \22A6 belongs in stylesheets, typically in content on ::before or ::after.⊦, ⊦, or \22A6 in CSS.Explore More HTML Entities!
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